The present invent refers to an equipment destined to artificial ventilation in cases of respiratory insufficiency.
Pulmonary Ventilators are widely used in hospitals and related places. Due to the complexity of such device, they present high cost in reason of their constructive complexity, thereby limiting its acquisition to a larger number of users.
The Mini Pneumatic Mechanical Pulmonary Ventilator differs from the others, not in its purpose but in its practical aspect, which is based primarily in its constructive and operational simplicity. Its low cost also allows its acquisition both by entities and professionals that previously were unable to afford such and important equipment. The advent of such device will enable a larger number of professionals and health services to have access to an artificial ventilator that facilitates the transportation of patients and their care on the streets. It also completes the emergency units and can be used for the transportation of patients inside hospitals since it advantageously substitutes the manual lung ventilation, releasing therefore, the professional for other activities during an emergency.
Such device has the characteristic of liberating a high flow (around 90 liters/minute), allowing at the same time, restrict the air-way pressure (limited to 25 cm of water). This is a modern concept of lung ventilation denominated PCV (Pressure Control Ventilation). In practice there is an automatic flow adjustment due to pulmonary volume and air-way resistance that adequates the gas distribution impedance. Once the 25 cm of water pressure is reached, the flow is interrupted in the units which the pressure has entered in equilibrium with the generated pressure of the device, leaving a residual flow in the units which have not yet been filled, therefore reducing significantly the possibility of a pulmonary rupture (volutrauma or barotrauma).
Among other features this equipment also presents:
operation facility since it has just one control (frequency)
low consumption of gas (2,5 liters/minute for any age given group), which guarantees great autonomy;
small size;
low cost;
robustness;
safety usage: the VENTURI system which is used to dilute oxygen, limits the pressure of the air-way and remains opened during all respiratory cycle, enabling patient to breath independently and regardless of the device cycling.
Basically, the Mini Pneumatic Mechanical Pulmonary Ventilator is an astatic multi-vibrator, activated by conventional sources of pressurized gas such as oxygen or medical compressed air.
For the construction of pulmonary ventilators, multi-vibrators are used to generate square wave. In a ventilator, the high wave phase corresponds to the inspiratory phase and its duration is called inspiratory time. The low phase corresponds to the expiratory phase and its duration is called expiratory time. The sum of those two times corresponds to a respiratory cycle and the unit of time (minute) divided by that period is defined as the respiratory frequency. Other parameter in artificial ventilation is the ratio between these two periods of time, denominated the inspiratory: expiratory ratio (I: E ratio).
The variation of the flow released in the inspiratory phase allows the volume control of the gas, which is introduced in the lung during inspiratory time. In order to avoid mechanic trauma in the lungs by excessive pressure, the ventilators must have a pressure controlling system.
In the Mini Pneumatic Mechanical Pulmonary Ventilator, such controls are simplified as follows:
flowxe2x80x94during the inspiratory phase a fixed flow goes through the injector which is amplified by the VENTURI system thus allowing its automatic adjustment, as previously described;
air-way pressurexe2x80x94the VENTURI system is designed in such a way as to limit the pressure to 25 cm of water;
I:E ratioxe2x80x94it is fixed in the range of 1:2 to 1:2.5 during the device assembling;
Control of respiratory frequencyxe2x80x94this is the only control to be adjusted by the operator. In order to make the operation easier, pictures of a sucking baby, a child and an adult have been printed beside the frequency control knob and one should match the knob with the printed picture that the case indicates;